The invention relates to a network architecture for various communication and data networks, providing value-added services for users.
These communication and data networks may have different physical characteristics. They may differ in terms of the type of access to the network functions provided and in terms of data transmission principles (e.g. the transmission protocols used and corresponding standards). Furthermore, they offer different services for the network user.
A physical network is understood below to refer to a conventional data or communications network, such as the circuit-switched fixed network (based on SS# 7, Central Channel Signaling System no. 7), the mobile radio network or a computer network such as the Internet, or a local network LAN, based on a communications protocol such as TCP/IP or Token Ring. The providers of the underlying network functions are referred to below as network operators.
A corporate network (internal company network or Intranet) designates below a data or communications network, or a network comprising a plurality of such networks, which is assigned to an organizational unit. It enables communication within this organization and is outwardly shielded by hardware, software or a combination thereof.
Network operators and service providers offer network users basic functions and services of the physical networks (basic services). “Value-added services” can be generated through integration of basic services (as a rule) of a network. These value-added services can then be sold directly to the user of the service provider (or to special service integrators, who in turn use basic services of service providers).
In the conventional fixed network and in the mobile radio network, for example, value-added services are implemented in addition to basic services along with conventional voice or data transmission by an “Intelligent Network”. These value-added services involve, for example, a unique telephone number for a user in the entire network (Universal Personal Number), toll-free telephone numbers (Freephone) or voting by telephone (Televoting). These value-added services are implemented by network elements provided centrally in the network (SSP, Service Switching Point, SCP, Service Control Point, etc). The description of the principles of an intelligent network can be found in the ITU protocol suite Q. 12xx.
This decentralized implementation of value-added services in a network produces a number of disadvantages. With high network utilization, the network elements responsible for the services present a bottleneck, since all service requests must pass via these network elements and be processed there. In the case of larger, well-utilized networks, this requires a correspondingly high investment in high-performance hardware, in particular for the centrally-controlling network elements (“bottleneck”), since only these elements can control traffic flow with delay times which remain acceptable.
In addition, high availability of the central network nodes such as the SCP, which is responsible for processing the service requests, must be guaranteed. Failure of a single network node of this type here entails the unavailability of all value-added services of the entire network.
For these reasons, the technology required to provide the value-added services can currently be provided by large network operators only. Smaller operators (e.g. City Carriers) on their own cannot make the investment in the necessary high-cost network elements. Use of the network elements by a plurality of service providers or service integrators is not currently possible, since separation of the different functionalities which are implemented in the central network nodes is not provided.
In addition, the different networks are physically separated from each other. In order to be able to use the services of the networks, a customer must switch between different service providers which, in individual cases, may also result in a change of terminal device. The provision of trans-network communication is possible only by gateways between the individual networks, whereby a connection must be established for each network gateway (e.g. fixed network to mobile radio network, ISDN to Internet) according to the protocols used on both sides.